(ORDO NEWS) — New geological evidence shows that the global catastrophe caused by the fall of the asteroid Chicxulub was accompanied by powerful earthquakes that continued for weeks, and possibly months after the impact.
About 66 million years ago, the 10-kilometer asteroid Chicxulub collided with the Earth, which finally ended the long era of the reign of dinosaurs.
The impact caused a catastrophe on a global scale, including the most powerful tsunami waves and earthquakes.
The new work showed that powerful seismic activity did not subside for weeks, or even months after the fall of a celestial body.
Hermann Bermúdez will report on this at the Geological Society of America’s GSA Connects meeting in Denver.
The energy of that impact is estimated at 1023 joules, tens of thousands of times higher than that of the massive 2004 Sumatran earthquake of magnitude 9.1.
The fall of the asteroid left a crater off the coast of modern Mexico, the diameter of which reaches 180-200 kilometers.
Bermudez and colleagues at Montclair State University have studied Cretaceous-Paleogene boundary deposits in the United States, Mexico, and Colombia.
On the Colombian island of Gorgona, they found tiny, rounded minerals, solidified blobs of glass ( tektites ), which appeared as a result of a collision.
Gorgon is located in the Pacific Ocean, 3000 kilometers from the epicenter of the ancient disaster.
Moreover, at that time the island did not yet exist, and these deposits accumulated deep on the ocean floor, only later rising to the surface.
This tektite-saturated layer of the Cretaceous-Paleogene boundary turned out to be strongly deformed, which indicates that strong shaking occurred then.
And since at that time it was deep at the bottom, where tektites could get only weeks or even months after the impact, the authors conclude that powerful seismic activity continued all this time.
Geologists also found evidence of this in other places where they explored the Cretaceous-Paleogene boundary. In Mississippi, Alabama, and Texas, it also retained deformations indicating earthquakes.
And in Mexico, traces of soil liquefaction are found – a process in which some rocks saturated with moisture behave like a dense liquid.
“Our data helps to better explain what happened at the end of the Cretaceous and the beginning of the Cenozoic,” the scientists summarize , “and point to some of the largest earthquakes that our planet experienced during the Phanerozoic.”
Recall that the Phanerozoic is called the current geological eon, which began with the Cambrian, almost 550 million years ago.
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